Medium priority:
Ability to assign an identity name (along with "your name" and "email" in "new identity: simple setup" screen), that will be shown while choosing the identity in composing a new message.
Currently, all identities are defined by their "your name" field only, and that is really annoying if you wish to use several identities for the same account, with the same information to be sent (i.e."your name"), except signature.
K9 has resolved that issue by adding an "identity name" as a key field to identify the identity.